This invention relates to a connection means, particularly for a suspended load, consisting of a roundsling and at least one coupling member associated therewith, which comprises a substantially U-shaped U-bolt and a releasable bridge member which extends crosswise with respect to the in-hung roundsling and by means of which the shanks of the U-bolt are connected with each other.
In connection with connection means of this kind, which are associated with conventional load hooks, coupling links, shackles and other coupling elements for lifting purposes, which have the same lifting capacity as such a roundsling, the drawback is encountered that all these parts have too small a radius of contact or curvature to allow their utilization together with the roundsling whereby its lifting capability at a predetermined safety factor is substantially reduced. This is elucidated with reference to FIGS. 1-6 of the annexed drawings. In FIG. 1 a roundsling of a well known kind is illustrated in cross section. The roundsling consists of a hank of at least one thread or the like which is made of one or more fibres 1 of polyester or the like which are wrapped together without interruption and united into an endless sling which is held together and protected by a tubular cover or sleeve 2. Even though known roundslings are alike in principle, their design varies a little. Such a roundsling is generally applied around a loed and is subsequently hung into a load hook at its utilization for lifting purposes. These roundslings have a drawback, since they cannot be applied around sharp edges or around parts having too small a radius, without entailing a considerable reduction of their lifting capacity.
Conventional load hooks, coupling members, shackles and other elements for lifting purposes which have the same lifting capability as such a roundsling have, however, too small a radius of contact or curvature to permit their utilization together with the roundsling without a considerable reduction of the lifting capability with maintained safety factor. This is illustrated in FIGS. 2-6.
FIGS. 2 and 3 illustrate in plan view and a partly cross-sectional view, respectively, the connection of the roundsling 3 to a U-bolt or shackle 20 having the same lifting capability as the roundsling.
FIGS. 4 and 5 illustrate in plan view and a partly cross-sectional view, respectively, the roundsling 3 being introduced into a conventional load hook 30 having the same lifting capability as the roundsling.
FIG. 6 illustrates the coupling of a roundsling 3 to a coupling member with the same lifting capability.
In everyone of the above, known cases the radius of contact, i.e. the radius of curvature of the surface (in the cross sectional plane of the coupling member determined by the roundsling), which is in contact with the roundsling, is too small. This is due to the fact that the most peripheral fibres of the sling are subjected to a considerably greater tension than the inner fibres, as is indicated by double-headed arrows e.g. in FIG. 3. These peripheral fibres therefore start rupturing first; after this weakening all other fibres, too, will soon rupture on account of overloading.